In general, the conventional liquid crystal displays may be classified into a transmissive type, a reflective type, and a transflective type according to the display manners thereof.
The transmissive type of liquid crystal display needs a backlight source disposed therein, and brightness can be brought to a panel of the display only when the light generated from the backlight source transmits through the panel. Therefore, it is hard to achieve the normal display via the transmissive type of liquid crystal display when the transmissive type of liquid crystal display is used in external environment, such as outdoors, where the light is relative stronger. It is needed for the reflective type of liquid crystal display to apply a reflective film to a lower glass substrate of the panel, and the display is achieved by reflecting the light in external environment. The reflective type of liquid crystal display has less power consumption than the transmissive type of liquid crystal display, since it has no backlight source; but some problems such as poor display quality may be caused when the light in the external environment, i.e., the light source, is faint. Therefore, the transflective type of liquid crystal display, which has the functions of both the transmissive type of liquid crystal display and the reflective type of liquid crystal display, has drawn wide attentions. When the light in external environment is strong, the panel reflects the incident light from the external environment to reach the object of emitting light; but when the light in external environment is faint, the panel reaches the object of emitting light using the backlight source, so that the transflective type of liquid crystal display has better outdoor visibility and a reflective effect, and thus has much wider use.
A transflective color filter substrate is an important member in the transflective type of liquid crystal display, and the reflective effect of the transflective color filter substrate on the light in external environment influences directly the display effect of the transflective type of liquid crystal display.
In general, a transparent substrate 1, a black matrix 2, three color filter films 3, 4, and 5 (corresponding to three primary colors of red, green, and blue, respectively), a reflective film 6, an insulating layer 7 (i.e., an OC layer), and a common electrode layer 8 (i.e., an ITO layer) are disposed in the structure of the conventional transflective color filter substrate (using the three primary colors of red, green, and blue as examples) as shown in FIG. 1. The manufacture process of the transflective color filter substrate having the above structure needs 5 mask exposures, which comprise: firstly coating a black photoresist on the transparent substrate, then performing the first mask exposure, and forming the black matrix (BM) having openings on the transparent substrate after developing; next performing the second mask exposure to form a first type of color filter films in the openings of the BM; then performing the third and fourth mask exposures in the same way to form the other two types of color filters in adjacent openings of the BM; and then sputtering a metal layer of the reflective film and coating a photosensitive resin (i.e., PR adhesive) on the color filter film and the BM, and forming the reflective film 6 located on the BM and having a certain pattern after subjected to the fifth mask exposure, a developing and wet etching. At last, the insulating layer 7 and the common electrode layer 8 are formed.
FIG. 1 is a cross-section view of a transflective color filter substrate manufactured using the conventional process.
In the conventional process of forming the transflective color filter substrate, all the five mask exposures are performed on the front side of the color filter substrate (a side of the color filter substrate where the color filter films are disposed), i.e., the top of the color filter substrate, and need special masks to perform the exposures. The color filter substrate needs to be aligned with the masks precisely in the process; and once the mask shifts from the color filter substrate beyond a minute value, the upper and lower patterns will not match each other, and some serious problems, such as light leakage of the panel, abnormal display, and so on, will be caused. Therefore, the conventional process of manufacturing the transflective color filter substrate becomes relative complex.